Earlier, a witness told Reuters that up to three gunmen fired on about 40 people inside the Quebec City Islamic Cultural Center. Police put up a security perimeter around the mosque.
Quebec police confirmed the shooting at a Quebec mosque in a tweet, and police on the scene said there had been fatalities.
“There are many victims … there are deaths,” a Quebec police spokesman told reporters.
A police tweet said there were deaths and injuries and that suspects had been arrested.
“Why is this happening here? This is barbaric,” said the mosque’s president, Mohamed Yangui.
Yangui, who was not inside the mosque when the shooting occurred, said he got frantic calls from people at evening prayers. He did not know how many were injured, saying they had been taken to different hospitals across Quebec City.
In June 2016, a pig’s head was left on the doorstep of the cultural center.
Many of Quebec rising Muslim population are North African emigrants.
The face-covering, or niqab, became a big issue in the 2015 national Canadian election, especially in Quebec, where the vast majority of the population supported a ban on it at citizenship ceremonies.
Incidents of Islamophobia have increased in Quebec in recent years. In 2013, police investigated after a mosque in the Saguenay region of Quebec was splattered with what was believed to be pig blood.
In the neighboring province of Ontario, a mosque was set on fire in 2015, a day after an attack by gunmen and suicide bombers in Paris.